Machine for metering and delivering powder



Dec. 30, 1958 i w. HARTMANN 2,856,666

MACHINE FOR METER;NG AND DELIVERING PQWDER 7 Filed July 24, 1957 s Sheets-Sheet 1 Tic. 1.

\ INVENTOR.

' M/mw/r/a /7 4/?7M,44 /V ATME/VEI Dec. 30, 1958 I w. HARTMANN 2,

MACHINE FOR METERING AND DELIVERING POWDER Filed July 24, 1957 3 Sheets-Sheet 2 INVENTOR.

Dec. 30, 1958 w. HARTMANN 2,855,666

MACHINE FOR METERING AND DELIVERING POWDER Filed July 24, 1957 s sheets-sheet 3 INVENTOR. WALDEMAR fWIMAA/A ATTO QWE t tes at '51 6,666 MACHINE FOR METERIN G DELIVERING POWDER Unite Waldemar Hartmann, Mountain Lakes, N. J. Application July 24, 1957, Serial No. 673,872 3 Claims. (Cl, 30237 vice of the kind stated in which the amount of powder that is continuously delivered can be varied over wide limits, and in which the amount of powder so delivered can be controlled with a great degree of accuracy.

The device of the invention has immediate utility in the treatment of materials which require the admixture of small amounts of a treating agent in powdered form. An example of such treatment is the addition of small amounts of powdered spent sulfite liquor to agglomerated coal fines, as set forth in my United States Patent Number 2,778,718, dated January 22, 1957. The addition of measured amounts of powdered treating material to materials treated :in batch presents little or no difficulty. The addition of measured amounts of powders to material with which it is to be mixed in a continuous stream is difficult to control with any degree of accuracy, however, unless relative expensive weighing and conveying equipment is employed.

The invention herein provides a powder metering and delivering device which is inexpensive, sturdy and accurate, and which, moreover, is well adapted to the delivery of selected amounts of powder to materials being treated in a continuous process. Additional uses of the device, and other advantages thereof, will become apparent as the description thereof is read in connection with the several figures of the drawings in which like reference numerals indicate like partsand in which:

Fig. 1 is a plan view of the apparatus of the invention for metering and delivering powdered treating material, parts being broken away to show internal structure;

Fig. 2 is an elevational view of part of the apparatus shown in Fig. 1;

Fig. 3 is a'sectional view on the line 33 of Fig. 2;

Fig. 4 is a sectional view showing the principal parts of a powder metering device and related fan structure;

Fig. 5 is an enlarged detail view of a powder metering valve; and

Fig. 6 is a detail view of a metering valve component.

The powder metering .and delivering mechanism 3disclosed in Figs. '1 through 6 is designed to provide precise control over the amount of powdered material .that is delivered thereby. The treating agent in powdered form is placed into a closed hopper 10 from which it is metered into a delivery fan 12. The delivery fan 12 is adapted to discharge an air suspensionof the treating powder from its outlet.

Since some powdered materials are extremely sensitive -to atmospheric moisture, it is important that the same be kept dry and in flowable condition within the hopper. Accordingly, an electric heating coil 14 is located within the hopper 10 and by means of a thermostat 16 attached thereto, the coil 14 is maintained at a temperature in excess of 90 ';F. A control wire 18 connects the thermostat 1610 a suitable thermostatic control deviceatthe exterior of the hopper.

2,866,666 Peltented Dec. 30, 1958 Ice and also the delivery fan 12. Power is transmitted from one end of the motor shaft 28 to a speed reducing unit 30. Power from the output shaft 32 of the speed reducing unit 30 is transmitted to a drive wheel 34 of a transmission gear unit 36 associated with the hopper 10. The drive wheel 34 is attached to a drive shaft 38 (Fig. 2) which extends through the transmission gear unit 36 to provide driving power for the beater 20. Within the transmission gear unit 36, the drive shaft 38 has affixed thereto a gear 40 (Fig. 2) which gear is in contact with an idler gear 42 on the end of the powder delivery worm 26;

The powder delivery worm 26 extends across the bottom of the hopper 10, its remote end being mounted in anti-friction bearings 46 (Fig. 4) supported in a metering valve plate 48 which is fixed to the hopper housing. The delivery worm 26 comprises a shaft 56 which has a wire 52 helically wound thereabout and attached thereto. The shaft 50 has a pin 90 extending radially therefrom at a point in front of the bearing 46. The pin 90 sweeps the entrance to the bearing 46 and prevents an accumulation of powder which otherwise might be pressed into or otherwise find its Way into-the bearing as the shaft 56 isrotated, The metering valve plate 48 has a discharge aperture 54 formed therein at a point immediately below the shaft bearing 46 such that the helix 52 delivers powdered treating material to the discharge aperture 54.

The effective size of the discharge aperture 54 can be regulated by a manual control lever 56. The control lever is shown in Fig. 5 as comprising a base 58 which is the same size and shape as the plate 48. The base 58 has a discharge aperture 60 corresponding in size and location to the discharge aperture 54 of the plate 4%. Attaching lugs 62 of the base 58 correspond to similar attaching lugs 64 of the plate 48 such that the two can be attached to the hopper housing by means of common screws 66. The base 58 has a centrally located upstanding flange 68 on which the control lever 56 is mounted; the flange 68 being peened over to retain the lever 56 in operative relationship with the base 58. The control lever 56 has a notch 70 which corresponds in size and shape to the discharge apertures 54 and 60 of the plate 48 and the base 58, respectively. It can be seen, therefore, that rotation of the lever 56 about the bearing flange 68 will result in either closing or opening of the discharge apertures formed through the metering Valve plate 48 and the base 58. At its free end, the lever 56 has a pointer 72 which cooperates with a scale 74 such that the size of the opening between the hopper 10 and the delivery fan 12 is visually indicated.

The casing of the fan 12 is suitably attached to the outer face of the hopper 10 and provides a bearing-block 76 for an impeller shaft 78 which is driven by a drive wheel '80 and a belt connection to the opposite end of the motor shaft 28. The bearing block 76 has .a air of axially spaced anti-friction bearings 82 and .84 which support the impeller shaft 78. The free end of the impeller shaft 78, which extends into the casing of the de livery fan 12, has an impeller'86 fixed thereto. As a consequence of this arrangement, tpowderedetreating :material can be metered from vthe hopper ltlinto the delivery fan 12 and discharged from the .fan outlet .88 {(Eig. :1)

t the m te l u de tr a men The amount of powdered treating material that is to ures A", and sidewalls that measure be delivered at the delivery fan outlet must be capable of selective control as to its weight to accommodate the 'feed of powder to the material under treatment, or to the demands of other controlling considerations. The rate at which the treating material is metered into the delivery fan is determined not only by the size of the metering aperture, but also by the rate at which the shaft 26 within the hopper is rotated, both the metering opening and the speed of shaft rotation being adjustable. The speed reducing unit is of conventional structure and has a control lever 88 by which six speed changes can be obtained. In the instant apparatus, the motor shaft 28 rotates at 1750 R. .P. M. This speed can be reduced in the speed reducing unit 120 to 30, 68, 112, 117, 240 or 353 R. P. M., depending on the position of the control lever 88. ,The gear ratios within the transmission gear unit 36 are such that these outputs of the speed reducing unit 30 transmit to the shaft 26, 220, 500, 828, 1265, 1753 and 2647 R. P. M., respectively. It is, therefore, possible to correlate the size of the metering openingand the speed of the delivery 'shaft 26 such that the treating powder is delivered to the delivery fan at a predetermined rate. For example, the powdered spent sulfite liquor identified by the trade name Marabond, in my aforesaid patent, can be delivered from the hopper at a selected rate within the range of A 02. to 1 /2 ozs. per minute when the delivery shaft 26 is driven at 220 R. P. M., the selected rate depending, of course, on the setting of the control lever 56; within a range of A oz. to 1%, ozs. when the delivery shaft is driven at 500 R. P. M.; within a range of oz. to 2 A ozs. when the delivery shaft is driven at 828 R. P. M.; within a range of A oz. to 2 /2 ozs. when the delivery shaft is driven at 1265 R. P. M.; within a range of 4 oz. to 5 ozs. when the delivery shaft is driven at 1753 R. P. M.; and within a range of oz. to 11 ozs. when the delivery shaft is driven at 2647 R. P. M. The rate of feed at any delivery shaft speed is, of course, varied by changing the metering opening through rotation of the lever 56. The rate of feed of all of the treating powders at any delivery shaft speed and for any selected size of metering opening is so constant that tables can be compiled to show the rate of feed produced at any selected delivery shaft speed and metering opening.

In a typical illustrative installation, the metering opening 54 has a base that measures /s", an apex that meas- The delivery shaft is 5 in diameter, and the helical wire 52. arranged about the shaft 50 at a pitch of about tl'1 turn per inch, is in diameter. to has been used to meter and deliver, among other powders, a powdered spent sulfite liquor sold by Lake States Yeast Corporation under, its trade name Toranil B.

The characteristics of Toranil B are as follows:

Free flowing light tan powder apparent bulk-.

ing value 1 (#I/ftfi):

1 Modification of ASTM 029-42.

Percent increase lnweight when oven dry material is exposed at F. and 50% R. H.

In metering Toranil B, the metering valve of the installation referred to was set to various positions -while the delivery shaft 26 was rotated at various speeds, and it was found over a series of tests that the amount of The installation referred I powder delivered remained the same at any given valve opening and any selected shaft speed, all as indicated in the following tabulation in which #2 represents a delivery valve restriction to at its base and A at its apex; #4 represents a delivery valve restriction to atits base and Vs" at its apex; #6 represents a delivery valve restriction to 75 at its base and A at its apex; #8

represents a delivery valve restriction to at its base and A" at its apex; and #10 represents a delivery valve restriction to 5 at its base and 54" at its apex.

Material Delivery to Fan per minute, per metering opening Delivery Shaft Speed #2 #4. #6 #s #10 02. Oz. 02. Oz.

It will be noted, particularly by reference to Fig. 4,

that the powder delivery shaft 26, while driven from the same motor, is quite independent of the impeller shaft 78. This is an important consideration in the successful operation of the device herein for the reason that it permits the selective metering of the powder into the delivery fan 12 without reference to the rate at which the impeller shaft 78 is rotated. In other words, the impeller shaft 78 is adapted to be rotated at a constant speed, while the delivery shaft 26 is designed for operation at variable speeds. Thus, no matter what amount of powder is delivered into the delivery fan 12 by regulating the metering throat 54, the powder so delivered will be transported in the air stream from the fan at a constant speed.

In the above description, an illustrative embodiment has been set forth by way of explanation. It will be understood that modifications of the specific mechanisms and their relative proportions may be made in accordance with the spirit of the invention set forth herein. Accordingly, it is intended that this invention be limited only by the scope of the appended claims.

I claim:

1. In a device for metering closely controlled small quantities of finely powdered material, a receptacle adapted to hold a supply of powdered material, a fan casing fixed to one side of said receptacle, a rotatable powder delivery device including a shaft mounted near the bottom of said receptacle, an impeller shaft mounted for rotation in said fan casing in axial alignment with said shaft of said powder delivery device, an impeller having a plurality of radial blades mounted on said impeller shaft, a powder metering passage interconnecting said receptacle and said fan casing at a point adjacent said shafts whereby powder discharged therethrough is delivered to the axial region of said impeller, externally accessible and manually adjustable means for selectively restricting said metering passage, means for driving said impeller, and variable speed means for driving said powder delivery device.

References Cited in the file of this patent UNITED STATES PATENTS 1,495,479 Grindle May 27, 1924 1,781,509 Gurney Nov. 11, 1930 1,837,635 Van Deventer Dec. 22, 1931 

